Thanks for the reply! I have infact been talking to users as well as watching the logs and analyzing google analytics data. I do have some insights on whats missing but as I said, the real challenge is in designing interfaces that can solve these problems. For example how do I display primary and secondary information on a profile page. What should be emphasized and de-emphasized. Since these are common problems, I was wondering if there is a book or something that I can readup to get some answers/pointers. Profile page is one example. Pages like account setting or stats page are other common pages that should have some standard design patterns.
In regards to books, I would recommend at least checking out Steve Krug's Don't Make Me Think, possibly some other design orientated books and then read up upon usability in general.
You may wish to find a usability consultant too, or look for someone who hasn't used your app before with experience in this area to give you a few pointers.
